Intracerebral pituitary grafts in hypophysectomized hosts are capable of maintaining near-normal testicular weight. Immunocytochemical studies of grafts located in the 3rd ventricle indicate that they contain pars distalis cells immunoreactive for LH, TSH, ACTH, GH. and Prl. The grafts are not directly innervated by LRF or somatostatin fibers.